1. Field of the Invention
This invention relates to improved apparatus for stabilizing the foundation of an existing building structure which may or has experienced settlement or movement. More particularly, it is concerned with apparatus and a method for stabilizing the below-ground foundation of building or the like wherein a support is positioned in supporting relationship to the foundation, a screw anchor is driven into the ground adjacent the support, a lifting force is applied to the support in the foundation using the screw anchor as a base for such lifting force, and the support is thereafter affixed to the screw anchor.
2. Description of the Prior Art
Many homeowners face the disconcerting and oftentimes expensive problem of foundation settling. This phenomenon can arise by virtue of loose, sandy soil around the foundation, undue moisture conditions, expansive soils or improper original construction of the foundation. In any case, solving the settling problem and properly supporting the foundation (and usually the basement floor) is typically a very involved and costly proposition.
Various techniques have been proposed in the past for supporting below-grade structural footings. For example, U.S. Pat. No. 2,982,103 describes a system wherein a bracket is attached to the basement walls, and a hole is bored through the adjacent floor. Elongated pipe sections are hydraulically driven downwardly through the floor until a bearing region such as bedrock is reached, whereupon the pipe sections are coupled to the wall-mounted bracket. Such systems are very costly to install. Additional patents describing various underpinning methods using hydraulic rams are described in U.S. Pat. Nos. 3,902,326, 3,796,055, 3,852,970, and 4,634,319.
U.S Pat. Nos. 4,673,315 and 4,765,777 are exemplary of prior practices and systems wherein a piling is driven into the ground using a hydraulic ram until the piling encounters a predetermined resistance whereupon the ram is further actuated to raise the foundation or a slab a predetermined distance.
In addition, it has been known in the past to use embedded earth anchors as a means of supporting foundations or footings. For instance, anchors have been installed vertically beneath a footing, with plural anchors being interconnected with reinforced concrete. In other instances, plural anchors have been driven at various angles and tied together to the footing with reinforcing bars or hairpin connectors; such connection structure then being cast in concrete.
Despite these prior attempts, however, there is a distinct need in the art for an improved, easy to install system for providing load-bearing support for structural footings. Advantageously, such a system should be low in cost and readily installable from the outside of a house or other structure.